net/url_request/view_cache_helper.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
   6 #define NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
   7 #pragma once
   8
   9 #include <string>
  10
  11 #include "base/memory/weak_ptr.h"
  12 #include "net/base/completion_callback.h"
  13 #include "net/base/io_buffer.h"
  14 #include "net/base/net_export.h"
  15
  16 namespace disk_cache {
  17 class Backend;
  18 class Entry;
  19 }  // namespace disk_cache
  20
  21 namespace net {
  22
  23 class URLRequestContext;
  24
  25 class NET_EXPORT ViewCacheHelper {
  26  public:
  27   ViewCacheHelper();
  28   ~ViewCacheHelper();
  29
  30   // Formats the cache information for |key| as HTML. Returns a net error code.
  31   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  32   // operation completes. |out| must remain valid until this operation completes
  33   // or the object is destroyed.
  34   int GetEntryInfoHTML(const std::string& key,
  35                        const URLRequestContext* context,
  36                        std::string* out,
  37                        const CompletionCallback& callback);
  38
  39   // Formats the cache contents as HTML. Returns a net error code.
  40   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  41   // operation completes. |out| must remain valid until this operation completes
  42   // or the object is destroyed. |url_prefix| will be prepended to each entry
  43   // key as a link to the entry.
  44   int GetContentsHTML(const URLRequestContext* context,
  45                       const std::string& url_prefix,
  46                       std::string* out,
  47                       const CompletionCallback& callback);
  48
  49   // Lower-level helper to produce a textual representation of binary data.
  50   // The results are appended to |result| and can be used in HTML pages
  51   // provided the dump is contained within <pre></pre> tags.
  52   static void HexDump(const char *buf, size_t buf_len, std::string* result);
  53
  54  private:
  55   enum State {
  56     STATE_NONE,
  57     STATE_GET_BACKEND,
  58     STATE_GET_BACKEND_COMPLETE,
  59     STATE_OPEN_NEXT_ENTRY,
  60     STATE_OPEN_NEXT_ENTRY_COMPLETE,
  61     STATE_OPEN_ENTRY,
  62     STATE_OPEN_ENTRY_COMPLETE,
  63     STATE_READ_RESPONSE,
  64     STATE_READ_RESPONSE_COMPLETE,
  65     STATE_READ_DATA,
  66     STATE_READ_DATA_COMPLETE
  67   };
  68
  69   // Implements GetEntryInfoHTML and GetContentsHTML.
  70   int GetInfoHTML(const std::string& key,
  71                   const URLRequestContext* context,
  72                   const std::string& url_prefix,
  73                   std::string* out,
  74                   const CompletionCallback& callback);
  75
  76   // This is a helper function used to trigger a completion callback. It may
  77   // only be called if callback_ is non-null.
  78   void DoCallback(int rv);
  79
  80   // This will trigger the completion callback if appropriate.
  81   void HandleResult(int rv);
  82
  83   // Runs the state transition loop.
  84   int DoLoop(int result);
  85
  86   // Each of these methods corresponds to a State value. If there is an
  87   // argument, the value corresponds to the return of the previous state or
  88   // corresponding callback.
  89   int DoGetBackend();
  90   int DoGetBackendComplete(int result);
  91   int DoOpenNextEntry();
  92   int DoOpenNextEntryComplete(int result);
  93   int DoOpenEntry();
  94   int DoOpenEntryComplete(int result);
  95   int DoReadResponse();
  96   int DoReadResponseComplete(int result);
  97   int DoReadData();
  98   int DoReadDataComplete(int result);
  99
 100   // Called to signal completion of asynchronous IO.
 101   void OnIOComplete(int result);
 102
 103   scoped_refptr<const URLRequestContext> context_;
 104   disk_cache::Backend* disk_cache_;
 105   disk_cache::Entry* entry_;
 106   void* iter_;
 107   scoped_refptr<IOBuffer> buf_;
 108   int buf_len_;
 109   int index_;
 110
 111   std::string key_;
 112   std::string url_prefix_;
 113   std::string* data_;
 114   CompletionCallback callback_;
 115
 116   State next_state_;
 117
 118   base::WeakPtrFactory<ViewCacheHelper> weak_factory_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(ViewCacheHelper);
 121 };
 122
 123 }  // namespace net.
 124
 125 #endif  // NET_URL_REQUEST_VIEW_CACHE_HELPER_H_